Plastic packaging structures, such as plastic films, can be provided with adhesive coatings to enable an effective seal to be obtained. These adhesive coatings may be heat sealable at elevated temperatures; or they may be cold sealable at lower temperatures, typically from 0.degree. to 40.degree. C. In packaging heat sensitive materials, especially foodstuffs (such as candy, chocolates and ice cream) the use of heated elements must be avoided to prevent spoiling the packaged product.
Previous commercial cold sealable, pressure-sensitive coatings while not requiring the use of heated elements in the sealing process have high surface tack and a tendency to block.